CVE-2021-26035
[20210701] - Core - XSS in JForm Rules field
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field of the JForm API leads to a XSS vulnerability.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field of the JForm API leads to a XSS vulnerability.
- Record
CVE-2021-26035- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
[20210701] - Core - XSS in JForm Rules field
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field of the JForm API leads to a XSS vulnerability.
- Record
CVE-2021-26035- Updated
- 2026-11-02
EUVDEUVD-2021-12858 No score
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field of the JForm API leads to a XSS vulnerability.
- Record
EUVD-2021-12858- Updated
- 2026-11-02
GitHub AdvisoriesGHSA-2vpx-cqm4-rqhq No score
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field...
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field of the JForm API leads to a XSS vulnerability.
- Record
GHSA-2vpx-cqm4-rqhq- Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field of the JForm API leads to a XSS vulnerability.
- Record
CVE-2021-26035- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVBIT-joomla-2021-26035 No score
[20210701] - Core - XSS in JForm Rules field
An issue was discovered in Joomla! 3.0.0 through 3.9.27. Inadequate escaping in the rules field of the JForm API leads to a XSS vulnerability.
- Record
BIT-joomla-2021-26035- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
joomlaBitnami |
3.0.0 to 3.9.27 | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-26035 is a medium vulnerability (CVSS 6.1) in Joomla Joomla\!, published July 7, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.72%, the 54th percentile. No source names a fixed version.